An Illustrated Flora of the Northern United States, Canada and the British Possessions/Polypodiaceae

Indusium small or inconspicuous, the divisions narrow or filiform. Stipes jointed near the base; filiform divisions of the indusium more or less inflexed over the sporanges. Blades with more or less rusty chaff underneath. Blades glabrous or nearly so. Blades oblong-lanceolate; divisions of the indusium numerous. Blades linear or linear-lanceolate; divisions of the indusium few. Stipes not jointed; divisions of the indusium spreading, mostly concealed beneath the sporanges. Puberulent, usually hispidulous; indusium deeply cleft into narrow flaccid segments. Glabrous; indusium divided to the center into a few short whitish turgid beaded hair-like segments. Indusium ample; the divisions broad, early spreading.

Blades lanceolate, broadly lanceolate, or narrowly deltoid-lanceolate, 2-3-pinnate. Blades broadest at base, long-tapering, bearing bulblets beneath. Blades scarcely broader at base, short-pointed; no bulblets. Blades deltoid-ovate, 3-4-pinnate.

Leaves simply pinnate. Lower pinnae gradually much reduced; upper (soriferous) pinnae conform. Lower pinnae scarcely reduced; upper (soriferous) pinnae of fertile fronds contracted. Leaves bipinnatifid or bipinnate. Leaves coriaceous, the pinnae deeply lobed at their base. Leaves herbaceous, fully bipinnate.

Indusia present (§ Eudryópteris). Texture membranous; veins simple or once forked. Lower pinnae gradually and conspicuously reduced. Lower pinnae scarcely reduced. Veins once or twice forked. Veins simple. Texture firmer, sometimes subcoriaceous; veins freely forked. Blades 2-pinnatifid or 2-pinnate; segments not spinulose. Leaves small; rachis commonly chaffy throughout. Leaves larger, 1½°-5° high; rachis naked or deciduously chaffy. Indusia flat, thin. Blades narrow, linear-oblong to lanceolate; sori nearly medial. Blades broader, narrowly oblong, ovate or triangular ovate; sori near midvein. Apex attenuate; pinnae broadest at base; sori 3-7 pairs. Apex short-acuminate, often abruptly so; pinnae broadest above the base; sori 6-10 pairs. Indusia convex, firm. Sori near the margin. Sori near the midvein. Blades 2-pinnate to 3-pinnate ; segments spinulose or mucronate. Blades ovate-lanceolate, triangular, or broadly oblong, usually not narrowed below. Indusia glabrous or nearly so; pinnae usually somewhat oblique to the rachis, the lowest broadly and unequally ovate to triangular. Pinnules flat, decurrent ; sori terminal on the veinlets ; scales pale brownish. Pinnules concave, some not decurrent ; sori mostly subterminal ; scales dark brownish. Indusia glandular ; pinnae usually at right angles, the lowest unequally lanceolate to ovate-lanceolate. Blades elongate-lanceolate, usually narrowed below. Indusia wanting (§ Phegopteris). Basal pinnae sessile or partially adnate : rachis more or less alate. Blades usually longer than broad; rachis and midveins freely chaffy; under surfaces pilose. Blades usually broader than long; rachis and midveins scarcely scaly; under surfaces slightly pubescent. Basal pinnae long-stalked; rachis not alate. Blades nearly horizontal, glabrous or nearly so, subternate, the basal pinnae approaching the terminal portion in size. Blades suberect, copiously glandular, triangular-ovate, the basal pinnae considerably smaller than the terminal portion.

Rootstocks stout, clustered, ascending; fertile segments linear. Rootstocks slender, creeping; fertile segments much broader.

Blades pinnate or 2-pinnate with large pinnules. Blades small, 3-pinnate, the pinnules narrow.

Blades nearly glabrous. Blades hirsute or tomentose. Blades hirsute and glandular; indusia discontinuous. Blades tomentose; indusia mostly continuous. Blades 2'-5' long; stipes slender; indusia herbaceous. Blades 6'-15' long; stipes stout, tomentose; indusia membranous.